The present invention is directed to the art of optically transmissive bodies, specifically to an optically transmissive dental impression tray.
Optically transmissive bodies, including both filamentous and other body types have found use in many applications. One particular application for which optically transmissive bodies have been used is in the transmission of light, i.e. as an illuminator.
An illuminator is a device where the light, which is normally traversing longitudinally through the optically transmissive body, is diverted laterally outward from the body at various points to illuminate given areas. Illuminators are formed by modifying an optically transmissive body to emit an incremental amount of the light outward from discrete portions of the body. Thus by using only a single light source, i.e., a bulb, numerous points of light can be obtained using an optically transmissive body prepared to emit light in this manner.
There are numerous methods by which an optically transmissive body can be prepared to emit light from discrete portions. For example, the optically transmissive body can be cut with grooves at various points along its length, with one or more of the groove surfaces coated with a reflective material. This reflective material will reflect any light which impinges upon it. By properly positioning the grooved surfaces light can be directed outward from any desired position along the body.
Mirrors angularly embedded in or laid along the optically transmissive body can be substituted for the reflectively coated groove surfaces. Optically transmissive bodies modified in this manner will transmit light in a similar manner as the light impinges upon the mirrored surfaces.
Examples of optical illuminators prepared by the discussed techniques are generally disclosed in U.S. Pat. Nos. 4,052,120 issued to Sick et al.; 4,173,390 issued to Kach; and 4,196,962 issued to Sick.
Another example of an optical illuminator is where a optically transmissive body is coated along a portion of its peripheral surface with an illuminant material. This illuminant material functions as a secondary light source by either radiating or reflecting light. By properly positioning this coating the light can be emitted in any direction from out of the body. A fiber optic illuminator prepared by this technique is disclosed in U.S. Pat. No. 4,128,332 issued to Rowe.
Another technique of modifying a optically transmissive body to cause the emission of light involves roughening a portion of the peripheral surface of the optically transmissive body. The light will pass out through this roughened surface. A fiber optic prepared in this manner is disclosed in U.S. Pat. No. 3,829,675.
Optically transmissive bodies have also been prepared, as disclosed in U.S. Pat. No. 4,172,631 issued to Yevick, to possess spaced apart longitudinal reflecting surfaces. As disclosed in Yevick, optic fibers which have been formed with grooves are laid upon a rigid reflective material, which possess ridges formed to be compatible with the grooves of the fiber. The finished product thus includes a multiplicity of mirrored surfaces positioned along the length of the fibers. The height or depth of these surfaces are specifically calculated to radially inwardly reflect an incrementally increasing quantity of the total light passing through the fiber. This light will pass across and through the opposite side of the fiber.
While optical illuminators prepared by the discussed techniques emit some of the light passing therethrough the degree of light emitted is not always adequate for an intended purpose. Further these discussed methods of preparing optical illuminating devices are generally costly. That is, the cost of imbedding mirrors into a optically transmissive body, or of coating previously provided grooved surfaces for certain applications is cost prohibitive.
A recent application of the technology for preparing optically transmissive bodies is in the field of dental impression trays. A particular type of optically transmissive dental tray is disclosed in U.S. Pat. No. 4,553,936, issued to Wang on Nov. 19, 1985. The dental tray disclosed in this patent transmitts actinic light to a channel formed in the tray which can hold a light polymerizable material. The disclosed material is cured by light activated polymerization.
While the dental tray disclosed in the Wang patent is useful for preparing a dental impression using a light polymerizable material, the amount of light transmitted to the channel for affecting this polymerization varies and is not evenly distributed throughout the tray channel. Thus the material is unevenly polymerized. It is thus apparant that the useability of an optically transmissive dental tray for preparing dental impressions is dependent upon the optical illuminating properties of the tray. The technology disclosed in the Wang patent does not add to the technology of preparing an illuminating optically transmissive body previously discussed, but merely applies this technology in preparing dental impression trays.